RU2553076C2 - Configuration of control channels in mobile communication system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to a method, an apparatus and a system for configuring control channels in a mobile communication network and at a mobile station. The invention provides aligning the size of the control channel information of different formats with an equal number of coded control channel information bits and/or modulation symbols for each control channel. The control channels may contain scheduling-related control information. According to another aspect of the invention, a more flexible solution is proposed which allows taking different geometries of mobile stations in a cell into account. Similar to the aspect above, the size of the control channel information is aligned through modulation and/or coding, although the control channel information is aligned to one out of a set of numbers of coded control channel information bits and/or modulation symbols for each control channel.

EFFECT: improved control channel configuration scheme, particularly control channels relating to transmission of user data.

4 cl, 19 dwg, 14 tbl

Description

Technical field

The invention relates to a method, apparatus and system for configuring control channels in a mobile communication network and a mobile station.

State of the art

Packet Dispatch and Public Channel Transfer

In wireless communication systems where packet scheduling is used, at least part of the resources of the radio interface is dynamically assigned to different users (mobile stations - MS). These dynamically allocated resources are typically mapped to at least one shared data channel (SDCH). The public data channel may, for example, have one of the following configurations:

- One or more codes in a CDMA (Code Division Multiple Access) system is dynamically shared by multiple MSs.

- One or more subcarriers (subbands) in an OFDMA (Orthogonal Frequency Division Multiple Access) system is dynamically shared by multiple MSs.

- Combinations of the above in the OFCDMA (Orthogonal Frequency Code Multiplexed Access Multiplexing) or MC-CDMA (Multi-Carrier Code Division Multiple Access) system are dynamically shared by multiple MSs.

The main advantages of packet scheduling are the benefits of multi-user diversity due to time domain scheduling (TDS) and the dynamic adaptation of user speed.

Assuming that the channel conditions of users change over time due to fast (and slow) decay, at this point in time, the dispatcher can assign available resources (codes in the case of CDMA, subcarriers / subbands in the case of OFDMA) to users who have good channel conditions for dispatching in time area.

Features of DRA and Public Channel Transmissions in OFDMA

In addition to employing multi-user diversity in the time domain by scheduling in the time domain (TDS), OFDMA can also apply multi-user diversity in the frequency domain by scheduling in the frequency domain (FDS). The fact is that the OFDM signal is built in the frequency domain from multiple narrow-band subcarriers (usually combined into subbands), which can be dynamically assigned to different users. Thus, the frequency-sensitive properties of a channel due to multipath propagation can be used to dispatch users at frequencies (subcarriers / subbands) at which they have good channel quality (multi-user diversity in the frequency domain).

As was briefly mentioned above, in real systems, OFDM (A) physical resources (subcarriers in the frequency domain and OFDM symbols in the time domain) are defined with respect to subbands in the frequency domain and slots, subframes, etc. in the time domain. For illustrative purposes, the following definition uses the following definition (see also 3GPP TS 36.211 V0.2.1, “Physical Channels and Modulation (Release 8),” November 2006, available at http://www.3gpp.org and included in this description by reference):

- the slot is set in the time domain and spans N _sym consecutive OFDM symbols

- the subframe is set in the time domain and spans N _{slot of} consecutive slots

- the frame is set in the time domain and spans N _sf consecutive subframes

- the resource element (RE) defines the resource of one OFDM symbol in the time domain and one subcarrier in the frequency domain, which defines one modulation symbol

- the subband is set in the frequency domain and covers N _sc consecutive subcarriers

- a block of physical resources (PRB) covers one subband and one slot and contains N _sym × N _sc resource elements

- the block of virtual resources (VRB) has the same size as the PRB in relation to the elements of the resource, but is not related to the mapping to physical resources.

Figure 3 shows an illustrative OFDMA channel downlink resource grid by which the resource block structure will be explained in more detail. For illustrative purposes, consider the frame structure, for example, proposed in 3GPP TR 25.814, “Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA), (Release 7)”, version 7.1.0, September 2006 (available at http : //www.3gpp.org and incorporated here by reference) or 3GPP TS 36.211.

символов OFDM во временной области и охватывает всю доступную ширину полосы канала нисходящей линии связи (т.е. все

поднесущих, на которые делится ширина полосы канала нисходящей линии связи). Каждый из символов OFDM состоит из

символов модуляции или элементов ресурса.Accordingly, a frame may, for example, have a length (in the time domain) of 10 ms and consist of 10 subframes 1.0 ms long. Each subframe can be divided into two slots, each of which contains a given number

OFDM symbols in the time domain and covers the entire available downlink channel bandwidth (i.e., all

subcarriers into which the downlink channel bandwidth is divided). Each of the OFDM symbols consists of

modulation symbols or resource elements.

поднесущих) и заданным числом символов OFDM во временной области (или, точнее, символов модуляции из заданного числа символов OFDM в частотном диапазоне, задаваемого шириной полосы

поднесущих). Таким образом, блок ресурсов может иметь длину подкадра или слот подкадра во временной области. Кроме того, можно предположить, что данное число элементов ресурса в блоке ресурсов (соответствующее данному числу символов модуляции из

символов OFDM в блоке ресурсов) резервируется для сигнализации управления, тогда как остальные элементы ресурса используются для пользовательских данных.According to figure 3, the resource block is formed by a given number of resource elements or modulation symbols in the frequency range (defined by the bandwidth

subcarriers) and a predetermined number of OFDM symbols in the time domain (or, more precisely, modulation symbols from a given number of OFDM symbols in the frequency range specified by the bandwidth

subcarriers). Thus, the resource block may have a subframe length or a subframe slot in the time domain. In addition, we can assume that a given number of resource elements in a resource block (corresponding to a given number of modulation symbols from

OFDM symbols in the resource block) is reserved for control signaling, while the remaining resource elements are used for user data.

For 3GPP Long Term Evolution (see 3GPP TR 25.814), a 10 MHz system (normal cyclic prefix) can consist of 600 subcarriers with a subcarrier width of 15 kHz. Then 600 subcarriers can be grouped into 50 subbands (12 adjacent subcarriers), each subband occupying a bandwidth of 180 kHz. Based on the fact that the slot has a duration of 0.5 ms, the resource block (RB) covers 180 kHz and 0.5 ms according to this example.

Several physical channels as well as reference signals are mapped to physical resources (RE, PRB). Below we will focus on the common data channel (SDCH) and the L1 / L2 control channels, which carry Layer 1 and Layer 2 control information for data on the SDCH. For simplicity, the mapping of other channels and reference signals is not considered.

Typically, a block of physical resources is the smallest unit of allocation of physical resources to which the SDCH is mapped. In the case when blocks of virtual resources are specified, first the SDCH can be mapped to a block of virtual resources, and then the block of virtual resources can either be mapped to one block of physical resources (local mapping) or distributed across multiple blocks of physical resources (distributed mapping).

To use multi-user diversity and to achieve a gain from scheduling in the frequency domain, the data of a specific user should be allocated on blocks of physical resources on which users have a good channel state (local mapping).

An example of a local display is shown in FIG. 1, where one subframe spans one slot. In this example, adjacent blocks of physical resources are assigned to four mobile stations (MS1 to MS4) in the time domain and in the frequency domain.

Alternatively, users can be allocated in distributed mode (DM), as shown in FIG. In this case, the user (mobile station) is allocated on multiple resource blocks that are distributed over a range of resource blocks. In distributed mode, several different implementation options are possible. In the example shown in FIG. 2, a pair of users (MS 1/2 and MS 3/4) share the same resource blocks. Several additional possible illustrative implementations can be found in 3GPP RAN WG # 1 Tdoc R1-062089, "Comparison between RB-level and Sub-carrier-level Distributed Transmission for Shared Data Channel in E-UTRA Downlink", August 2006 (available at http://www.3gpp.org and incorporated herein by reference).

Note that it is possible to multiplex the local mode and distributed mode in a subframe, where the amount of resources (RB) allocated to the local mode and distributed mode can be fixed, semi-static (constant for tens / hundreds of subframes), or even dynamic (varying from subframe to subframe )

In local mode, as well as in distributed mode, in this subframe one or more data blocks (which, by the way, are called transport blocks) can be allocated individually to the same user (mobile station) on different resource blocks that may belong to or Do not belong to the same service or automatic repeat request (ARQ) process. Logically, this can be seen as a selection of different users.

Link Adaptation

In mobile communication systems, link adaptation is a technical solution that can benefit from dynamic resource allocation. One link adaptation method involves AMC (adaptive modulation and coding). In this case, the data transfer rate to the data block or to the scheduled user is dynamically adapted to the instantaneous channel quality of the corresponding allocated resource by dynamically changing the modulation and coding scheme (MCS) in accordance with the channel conditions. This may require evaluating the channel quality at the transmitter for the link to the appropriate receiver. Usually mixed ARQ (HARQ) methods are applied optionally. It may also make sense to use fast / slow power control in some configurations.

Alarm Control L1 / L2

In order to inform the scheduled users of their resource allocation status, transport format, and other information related to user data (e.g., HARQ), the Layer 1 / Level 2 (L1 / L2) control signaling is transmitted in a downlink (e.g., together with user data ) Thus, it can be considered that each user (or group of users identified by the group ID) is assigned a single L1 / L2 control channel to provide L1 / L2 control information to the corresponding user (s).

In general, the information transmitted through the L1 / L2 control signaling can be divided into the following two categories: public control information (SCI) carrying information Cat. 1, and dedicated control information (DCI) carrying information Cat. 2/3. The format of these types of control channel information is specified, for example, for user data transmission on the downlink in 3GPP TR 25.814:

Table 1 Field The size Comment cat. 1 (Resource Indication) ID (for UE or group) [8-9] Indicates the UE (or UE group) for which data transfer is intended Assigning Resources Ffs Indicates which (virtual) resource blocks (and layers in the case of multi-level transmission) should (us) demodulate the UE. Duration of appointment 2-3 The validity period of an assignment can also be used to control TTI or continuous scheduling. cat. 2 (transport format) Multiple Antenna Information Ffs The content depends on the choice of MIMO schemes / beamforming. Modulation scheme 2 QPSK, 16QAM, 64QAM. In the case of multi-level transmission, multiple instances may be required. Payload size 6 The interpretation may depend, for example, on the modulation scheme and the number of assigned resource blocks (see HSDPA). In the case of multi-level transmission, multiple instances may be required. cat. 3 (HARQ) If accepted asynchronous mixed ARQ Mixed ARQ Process Number 3 Specifies the mixed ARQ process that the current transfer is accessing. Redundancy Version 2 To support increasing redundancy. New data indicator one For carrying out soft buffer cleaning. If synchronous mixed ARQ is accepted Retransmission Sequence Number 2 It is used to obtain the version with redundancy (to support increasing redundancy) and the 'new data indicator' (to implement soft buffer cleaning).

Similarly, 3GPP TR 25.814 also provides an L1 / L2 control signaling format for transmitting user data on the uplink:

table 2 Field The size Comment Assigning Resources ID (for UE or group) [8-9] Specifies the UE (or group of UEs) for which the allocation is intended Assigning Resources Ffs Indicates which uplink resources, local or distributed, can be used by the UE to transmit data on the uplink. Duration of appointment 2-3 The validity period of the appointment. Use for other purposes, for example, to control continuous scheduling, the operation for each process, or the length of the TTI, is FFS. Transport Format (TF) Transmission Options Ffs The uplink transmission parameters (modulation scheme, payload size, MIMO related information, etc.) that the UE should use. If the UE can select a transport format (part of it), this field defines the upper limit of the transport format selected by the UE.

As follows from the above tables 1 and 2, the number of bits of the control information varies depending, for example, on the connection of the control channel information with user data transmissions on the uplink or downlink.

In addition, some control channel information format fields may also depend on the MIMO transmission mode for the data. For example, if data is transmitted in a special MIMO mode (many inputs and many outputs), the L1 / L2 control information for this data may contain information related to multiple antennas, while this information can be omitted for data transmission without MIMO. But also for different MIMO schemes (for example, single-user (SU) MIMO or multi-user (MU) MIMO) and configurations (for example, rank, number of threads), the control channel information (before encoding) can be different (also according to the number of bits).

For example, data on a dedicated PRB may be transmitted to the UE using multiple codewords. In this case, it may be necessary to signal HARQ-related information, payload size and / or modulation scheme several times. In addition, MIMO related information may include precoding related information, where the amount of necessary precoding information depends on the use of single-user MIMO or multi-user MIMO, on the rank and / or number of streams.

Similarly, the format (and size) of the L1 / L2 control information may also depend on whether the control channel information relates to data transmission in a distributed or local OFDM transmission mode.

In traditional systems (for example, in a UMTS-HSDPA high-speed packet data access system), scheduling control information is typically transmitted using a fixed modulation and coding scheme (MCS), which is known to all mobile stations in a radio cell.

The use of a fixed modulation and coding scheme for L1 / L2 control signaling leads to the fact that different amounts of resources must be used for L1 / L2 control signaling on the resources of the physical channel, which, however, is undesirable due to the complexity of the UE, the flexibility of scheduling, etc.

Disclosure of invention

One solution to mitigate this problem may be to provide the mobile stations with a map indicating the use of downlink L1 / L2 control channel resources for each subframe (for example, in the form of so-called Cat. 0 control information). However, this approach may be undesirable because it may require additional complication of the mobile station, may lead to additional delay in processing the control channel information at mobile stations, and may also require additional overhead associated with sending a map indicating the use of L1 / L2 control channel resources downlink.

Another solution may only allow the allocation of a predetermined combination of the mobile station (for example, with a predetermined MIMO mode / configuration). However, this approach may impose an unacceptable restriction on scheduling functions and lead to a significant reduction in system throughput.

Another solution may not include sending a card indicating the use of downlink L1 / L2 control channel resources for each subframe (i.e., information of Cat. 0) and not provide a prior assignment. Thus, this approach requires that mobile stations try to blindly decode all possible combinations of modulation and coding schemes and mappings on resource elements to read different control channels in a subframe. Accordingly, this approach will lead to a significant and potentially undesirable complication of mobile stations.

The main objective of the invention is to propose another improved scheme for configuring control channels, in particular control channels associated with the transmission of user data.

The main task is solved by means of the subject of independent claims. Preferred embodiments of the invention are the subject of the dependent claims.

One main aspect of the invention, therefore, involves aligning the size of the control channel information of different formats with an equal number of bits of encoded control channel information and / or modulation symbols for each control channel. The control channels may, for example, contain control information related to scheduling, for example, L1 / L2 control information. According to another aspect of the invention, there is provided a more flexible solution that allows you to take into account different geometries of mobile stations in a cell. Similarly to the above aspect, the size of the control channel information is aligned by modulation and / or coding. However, in this illustrative aspect of the invention, the control channel information is aligned with one of a plurality of bits of encoded control channel information and / or modulation symbols for each control channel.

Another aspect of the invention provides for aligning the size of the information of the control channel of different formats with an equal number of bits of encoded information of the control channel and / or elements of the control channel for each control channel. Thus, a control channel element (CCE) corresponds to a given number of modulation symbols or resource elements. Thus, the terms “given number of CCEs” and “given number of modulation symbols or resource elements” are essentially equivalent from a technical point of view, since one CCE contains, in turn, a given number of modulation symbols or resource elements.

Accordingly, if the application refers to the alignment of the size of the information of the control channel of different formats with an equal number of bits of encoded information of the control channel and / or modulation symbols for each control channel, this principle also applies to alignment of the size of information of the control channel of different formats with an equal number of control channel elements for each control channel.

One embodiment of the invention relates to a method that can be used to facilitate blind detection of multiple control channels in a receiver-side communication system. It is assumed that multiple control channels are provided, and that the control channel information on the control channels has different formats, for example, is structured differently and / or has different lengths. According to this embodiment, the transmitting entity of the communication system can apply a modulation and coding scheme to each control channel associated with the control channel information format for the control channel. Applying a modulation and coding scheme to the control channel leads to the corresponding generation of an equal number of bits of encoded control channel information (e.g., output by the encoder before modulation) and / or modulation symbols (e.g., output by the modulator) for each control channel.

Whether an equal number of bits of encoded control channel information and modulation symbols are generated for each control channel, or whether an equal number of modulation symbols are generated for each control channel, may, for example, depend on the processing of the control channel information and / or the configuration of individual objects (e.g., encoders, modulators , multiplexers, etc.).

In yet another embodiment of the invention, different control channel information formats on the control channels have different numbers of control channel information bits. In the extreme case, each of the different control channel formats has a separate number of control channel information bits.

In one embodiment, the application of a modulation and coding scheme comprises encoding control channel information at a coding rate provided by a modulation and coding scheme associated with a control channel format, and modulating the encoded control channels according to a modulation scheme produced by a modulation and coding scheme associated with a format of the corresponding control channel. In addition, at the stage of application of the modulation and coding scheme, it is possible to map bits of encoded control channel information or modulation symbols of control channels to a downlink physical channel resource for transmission. In one example, modulation symbols may be OFDM modulated and then mapped to a physical channel for transmission.

In one possible and illustrative implementation of the modulation and coding schemes used according to the invention, all modulation and coding schemes associated with control channel formats produce the same modulation scheme but different coding rates. In this illustrative implementation, the encoder can thus adapt the coding rate so that an equal number of bits of encoded control channel information and, due to the same modulation scheme in all modulation and coding schemes, also an equal number of modulation symbols for each control channel are generated modulator.

The control channel information may have different structures / formats. The format of the control channel information may, for example, depend on at least one of the following parameters:

- the relationship of the control channel to the MIMO scheme or beamforming scheme used or to be used to transmit user data,

- the relationship of the control channel to the transmission of user data on the uplink or downlink,

- the relationship of the control channel to the use of OFDM transmission in local mode or in distributed mode for transmitting user data.

Alternatively or optionally, the control channel may carry information related to the search call, or information related to the response to the uplink (random) access procedure.

In one illustrative embodiment, at least one receiver (control channels) is pre-configured with a specific MIMO scheme, and the receiver can detect in blind detection mode, whether OFDM transmission is in local mode or in distributed mode to transmit user data, and relates whether the control channel to transmit user data on the uplink or downlink to select the correct modulation and coding scheme for demodulation and decoding Nala management. For this reason, in this embodiment, by detecting the transmission mode and the ratio of the control channel information to the uplink or downlink, the receiver can determine the correct control channel format through blind detection and can decode the control channel information from the control channels (note that the receiver not all control channels may need to be processed - see below).

Alternatively, in yet another embodiment, the at least one receiver is pre-configured for transmission in local mode or in distributed mode. In this case, the receiver can use blind detection mechanisms to detect whether the control channel belongs to the transmission of user data on the uplink or downlink, and which MIMO or beamforming scheme is used to transmit user data, to select the correct modulation scheme and coding for demodulation and decoding of the control channel.

In some embodiments of the invention, the control channels carry information related to the transmission of user data. For example, this information may be control information related to scheduling, for example, L1 / L2 control information. Accordingly, in this example, the control channel can also be referred to as control channels related to scheduling, or control channels L1 / L2.

In yet another embodiment, the control channel carries an indication of a user data resource, an indication of the transport format of the user data and, optionally, information regarding the retransmission protocol used to transmit the user data. Alternatively or optionally, the control channel may also carry resource assignment for user data and uplink transmission parameters for user data and, optionally, information regarding a retransmission protocol used to transmit user data.

According to yet another embodiment, the control channels may carry control channel information related only to the downlink transmission, control channel information related only to the uplink transmission, or control channel information related to the downlink and uplink transmission .

The control channel information for the control channel may carry different types of information. For example, in the case where the control channels carry L1 / L2 control information, for example, information cat. 1, cat. 2 and, optionally, information cat. 3, different types of information carried by the control channel may be coded together.

In yet another embodiment, the transmitting entity may further transmit control channels on a downlink physical channel resource. As indicated above, the receiving entity can blindly detect at least a subset of the physical resources onto which control channels are mapped (for example, those physical resources onto which a subset of certain control channel information formats are transferred). Thus, the information available to the receiving object about modulation and coding schemes associated with different formats of control channel information on the control channels is used to limit the number of blind detection attempts.

Furthermore, according to one illustrative embodiment, the number of control channel information bits (or the control channel information format) of the control channel may be associated with one modulation and coding scheme according to a predefined configuration or according to a configuration message.

In an illustrative variation of this embodiment, pre-configuration is achieved by transmitting a higher-level message on a data channel to one or more receiving objects on a dedicated or public channel. This message may direct the corresponding receiving entity to perform blind detection only on a subset of the physical resources onto which control channels are mapped and / or on a subset of control channel information formats.

In an alternative embodiment, the configuration message may be, for example, a broadcast message transmitted over a broadcast channel to direct one or more receiving entities to perform blind detection only on a subset of the physical resources onto which control channels are mapped and / or on a subset of formats control channel information.

For example, a configuration message may be transmitted as a separate piece of control information over a separate control channel. In one illustrative implementation, a configuration message and control channels are transmitted in each subframe or slot.

In yet another embodiment, one or more receiving entities may be instructed to perform blind detection only on a subset of the physical resources onto which control channels and / or control channel information formats are mapped through pre-configuration and / or configuration message.

In addition, in yet another embodiment, the receiving entity may be configured to blindly detect only a subset of the physical resources onto which control channels are mapped and / or a subset of control channel information formats.

As indicated above, another aspect of the invention provides a more flexible configuration of the control channels, while not leading, for example, to an excessive increase in the necessary complexity of the mobile station, reducing the flexibility of scheduling, etc. Accordingly, in yet another embodiment, each control channel format is associated with a number N of modulation and coding schemes, where N> 1. In this embodiment, all modulation and coding schemes, when applied to control channels of respective formats, can respectively generate a given number from N different numbers of bits of encoded control channel information and / or modulation symbols. In one illustrative embodiment, the output sizes are integer multiples of the smallest output size to facilitate multiplexing of control channels.

Accordingly, in the case of applying a modulation and coding scheme to the control channels, one of N modulation and coding schemes associated with the format of the control channel can be selected. This selection can be made, for example, based on the geometry of the receiver in the radio cell or other parameters, for example, the intensity of the received signal, fading or frequency selectivity of the channel, the type of receiver or available transmit power. The selected modulation and coding scheme can be applied to the control channel information for the control channel.

Another embodiment of the invention provides for the display of control channels in different sizes of aggregation, i.e. in different numbers of modulation symbols or control channel elements. The control channel information bits of the corresponding control channel format are mapped to at least one of a plurality of aggregation sizes, in which each aggregation size is specified by the number of modulation symbols or control channel elements.

Accordingly, additional restrictions may be considered in this mapping. For example, control channel information bits of the corresponding control channel format can be mapped only to those aggregation sizes that give the coding rate for the control channel information bits satisfying this reliability criterion, for example, the desired maximum block error rate. Additionally or by way of another example, the control channel information bits of the corresponding control channel format can also be mapped only to those aggregation sizes that give the coding rate for the control channel information bits above the minimum coding rate or below the maximum coding rate. In another example, aggregation sizes are different from each other.

Another illustrative embodiment provides systems where different bandwidths can be used for transmission. In these systems, it can be advantageous if the control channel information bits of at least one control channel format will always be displayed in the same aggregation size or the same aggregation sizes, regardless of the system bandwidth.

In yet another embodiment of the invention, a subset of control channels for transmitting control information related to uplink user data transmission and a subset of control channels for transmitting control information related to user downlink transmission can be configured. This may be advantageous in that, for example, receiving entities that only monitor downlink services may need to process only those control channels that relate to user data transmissions on the downlink. Similarly, according to yet another embodiment, a subset of control channels can be configured to carry control information for transmitting user data with MIMO or in a specific MIMO mode.

In yet another embodiment of the invention, the control channel information for the control channel comprises a format identifier that can give the format of the control channel information for the corresponding control channel.

In an alternative embodiment, the control channel information for the control channel contains a format identifier that can give the format of the control channel information for the corresponding control channel if multiple formats exist for a given size of control channel information bits.

In addition, it can be advantageous if, for control channels carrying control channel information containing MIMO information, a higher level modulation and coding scheme (or only a higher coding rate) is used than for control channels carrying control channel information not containing MIMO management information.

In addition, it can be advantageous if, for control channels carrying control channel information containing more MIMO information, a higher level modulation and coding scheme (or only a higher coding rate) is used than for control channels carrying control channel information containing less MIMO management information.

According to yet another embodiment of the invention, a base station is provided for configuring multiple control channels in a mobile communication system. The base station may comprise a transmitting entity applying a modulation and coding scheme to each control channel associated with the control channel information format for the control channel, thereby correspondingly generating an equal number of bits of encoded control channel information and / or modulation symbols for each control channel.

In some embodiments of the invention, the base station further comprises an encoder for encoding control information at a coding rate provided by a modulation and coding scheme associated with a format of a control channel, a modulator for modulating coded control channels according to a modulation scheme output by a modulation and coding scheme associated with a format the corresponding control channel, and a display unit for displaying bits of encoded information of the control channel or modulation symbols to catch resource management in the physical downlink channel for transmission.

According to a variation of the embodiment, the base station also includes a multiplexer for multiplexing bits of encoded control channel information for different control channels before being modulated by a modulator. Alternatively, the multiplexer may multiplex control channel information bits for different control channels prior to being encoded by the encoder.

According to yet another embodiment, a base station is provided that is capable of implementing or participating in the implementation of the method steps to facilitate blind detection of control channels according to one of the different embodiments described herein and their variations.

According to yet another embodiment, a mobile station is provided for use in a mobile communication system. A mobile station may, for example, comprise a receiver for receiving at least a subset of a plurality of control channels from a resource of a physical downlink channel in which the control channels have different formats. The modulation and coding scheme associated with the format of the corresponding control channel is applied to the corresponding control channel by the transmitting entity. In addition, the mobile station may include a processing unit for blindly detecting a subset of control channels for reconstructing control channel information of a corresponding received control channel, in which modulation and coding schemes associated with different formats of control channel information on the control channels are used to limit the number blind detection attempts.

In yet another embodiment, the mobile station uses the following means of the mobile station to perform blind detection. The demultiplexing unit (demultiplexer) can be used to demultiplex the received signal of the respective received control channels into modulation symbols. In addition, the mobile station may comprise a demodulator for demodulating the modulation symbols into soft decision values and constructing a codeword consisting of a given number of bits of encoded control channel information, and a decoder for decoding bits of encoded control channel information (also referred to as a codeword) to obtain bits control channel information. Thus, at least one of the demultiplexing unit, demodulator, and decoder uses the information available to the mobile station about modulation and coding schemes associated with different formats of control channel information on the control channels, which are used to limit the number of blind detection attempts.

A mobile station according to another illustrative embodiment of the invention is capable of implementing or participating in the implementation of the steps of the method to facilitate blind detection of a control channel according to one of the various embodiments described herein and their variations.

According to yet another embodiment of the invention, there is provided a mobile communication system for transmitting multiple control channels having different formats. This system may comprise a transmitting entity (e.g., a base station described here) applying a modulation and coding scheme to each control channel associated with a control channel information format for the control channel, thereby generating an equal number of bits of encoded control channel information and / or modulation symbols for each control channel, and at least one receiving entity (eg, the mobile station described herein) for receiving at least a subset of the control channels .

Brief Description of the Drawings

The following is a more detailed description of the invention with reference to the accompanying drawings. Similar or corresponding elements in the drawings are denoted identically.

Figure 1 is an illustrative data transmission to users in the OFDMA system in local mode (LM) having a distributed display of L1 / L2 control signaling.

2 is an illustrative data transmission to users in an OFDMA distributed mode (DM) system having a distributed L1 / L2 control signaling mapping.

3 is an illustrative resource grid of an OFDM channel structure slot according to 3GPP TS 36.211.

4 is an illustrative resource grid of an OFDM channel subframe according to an embodiment of the invention.

FIG. 5 is an illustrative example of configuring a control channel using a single modulation and coding scheme for all control channels in the resource grid shown in FIG. 4.

6 and 7 are illustrative examples of configuring control channels in the resource grid shown in FIG. 4, according to various illustrative embodiments of the invention.

Figs. 8 and 9 are two illustrative control channel information processing structures for multiple control channels at the physical layer according to various embodiments of the invention.

Figure 10 - in accordance with an illustrative embodiment of the invention, the use of two different modulation and coding schemes having a common modulation scheme for equalizing the number of bits of encoded control information for control channel information for control channels, where the control channel information has different formats.

11 is in accordance with an illustrative embodiment of the invention, the use of two different modulation and coding schemes to equalize the number of modulation symbols of control channel information for control channels, where the control channel information has different formats.

Fig. 12 shows, in accordance with an illustrative embodiment of the invention, the use of different modulation and coding schemes to equalize the number of modulation symbols of control channel information for control channels with two numbers of modulation symbols, where the control channel information has different formats.

13 shows, in accordance with an illustrative embodiment of the invention, the use of different modulation and coding schemes to equalize the number of modulation symbols of control channel information for a control channel with two numbers of modulation symbols, where the control channel information has different formats, for example based on channel quality information.

Fig. 14 shows several different formats of control channel information and their mapping into a single code block size by modulation and coding according to an illustrative embodiment of the invention.

FIG. 15 shows several different formats of control channel information and their mapping into two different code block sizes by modulation and coding according to an illustrative embodiment of the invention.

FIG. 16 illustrates a mobile communication system according to one embodiment of the invention, in which ideas of the invention may be implemented.

FIG. 17 is another illustrative embodiment of the invention, where control channel information formats are mapped to different amounts of encoded control channel information and / or modulation symbols depending on the size of the format.

Fig. 18 is another illustrative embodiment of the invention, where control channel information formats are mapped to different amounts of encoded control channel information and / or modulation symbols depending on the size of the format and, optionally, another parameter, for example, channel quality.

FIG. 19 shows two illustrative OFDM channel subframe resource grids according to various embodiments of the invention, where in the left resource grid, the control channel is mapped in a distributed mode and in the right resource grid the control channel is mapped in local mode to OFDM channel resources.

The implementation of the invention

Various embodiments of the invention are described below. For illustrative purposes only, most embodiments are described in connection with the (enhanced) UMTS communication system according to SAE / LTE, discussed above in the Background Section. Note that the invention can be advantageously used, for example, in connection with a mobile communication system, for example, the SAE / LTE communication system described above, but the invention is not limited to use in this particular illustrative communication network.

поднесущих или поддиапазоном в частотной области и данным числом

символов OFDM во временной области. Кроме того, данное число символов OFDM или элементов ресурса/символов модуляции на подкадре можно зарезервировать для сигнализации управления (например, сигнализации управления, связанной с диспетчеризацией для пользовательских данных в секции пользовательских данных подкадра). Согласно варианту осуществления, показанному на фиг.4, в иллюстративных целях предполагается, что каналы управления обеспечены в первых трех символах OFDM подкадра (т.е. в этом примере, первых трех символах OFDM первого слота подкадра). Однако заметим, что можно использовать и другие отображения сигналов управления в физические ресурсы в подкадре.The following description relies mainly on the downlink channel structure explained in the Background section. In addition, in connection with the explanations given in the Background section, it can be assumed for illustrative purposes that two (or more) slots form a subframe, while a given number of subframes, in turn, form a frame on the channel. Figure 4 shows an illustrative OFDM channel subframe resource grid according to an embodiment of the invention, which is used to illustrate the subframe structure assumed for illustrative purposes in most embodiments described herein. As follows from figure 4, it is assumed that two slots form a subframe in the time domain. For this reason, it can be assumed that the subframe on the downlink OFDM channel consists of two resource blocks in the time domain; and each resource block is formed by a given number

subcarriers or subband in the frequency domain and a given number

OFDM symbols in the time domain. In addition, a given number of OFDM symbols or resource elements / modulation symbols per subframe can be reserved for control signaling (eg, control signaling related to scheduling for user data in a user data section of a subframe). According to the embodiment shown in FIG. 4, it is assumed for illustrative purposes that control channels are provided in the first three OFDM symbols of the subframe (i.e., in this example, the first three OFDM symbols of the first slot of the subframe). However, note that other mappings of control signals to physical resources in a subframe can be used.

As described in the Background Section, the use of a fixed modulation and coding scheme for L1 / L2 control channels may be unfavorable, since the control channel information will be displayed in different numbers of modulation symbols and, therefore, use different amounts of physical radio resources for transmission to depending on the size of the information of the control channel. This scenario is illustrated illustratively in FIG. 5 (note that the different resource element patterns in OFDM symbols associated with the control channel are intended to illustrate control channels for different users). 5, for illustrative purposes, it is assumed that the first three OFDM symbols of a resource block are reserved for user control channels. For this reason, depending on the size of the corresponding control channel information format, the number of physical resources (modulation symbols) for the respective control channels is variable. The disadvantage of this approach is that for blind detection to receive control channels on the side of the mobile station, a very complex receiver on mobile stations may be required. This is due to the fact that the possible positions of the control channels to be decoded depend on the formats of the control channel. Therefore, in this subframe, the receiver will need to blindly decode all possible combinations and positions of the control channel formats.

One major aspect of the invention provides for aligning the size of control channel information of different formats with an equal number of bits of coded control channel information, modulation symbols and / or control channel elements (CCE) for each control channel (CCE corresponds to a given number of modulation symbols, which can alternatively be called resource elements ) Thus, the number of attempts to blindly detect control channels can be reduced, since the position of control channels on physical resources may be known to mobile stations (or at least a limited number of possible positions exist).

Alignment of control channel information according to different formats can, for example, be achieved using different modulation and coding schemes for different control channels depending on the format of the control channel information on the corresponding channel. If, for example, the modulation scheme for all control channels is the same, this may mean that the encoder coding rate can be configured to output the same number of bits of encoded control channel information for each control channel so that the control channel information of each control channel also mapped to an equal number of modulation symbols. If the modulation scheme varies for control channels, the coding rate and modulation scheme can be selected for the corresponding control channel information format, so that the control channel information of all control channels is mapped to the same number of modulation symbols or CCE.

FIG. 6 shows an example of a possible configuration of a control channel in the resource grid shown in FIG. 4, according to an illustrative embodiment of the invention. 5, various resource element patterns in OFDM symbols associated with a control channel illustrate control channels of different users. In contrast to FIG. 5, the use of different modulation and coding schemes for control channels of different users according to the format of the control channel information on the respective channels makes it possible to equalize the use of physical resources of different control channels, i.e. all control channels are mapped to one number of resource elements / modulation symbols (6 resource elements / modulation symbols / CCE in the example of FIG. 6).

This can facilitate blind detection of the control channels on the receiver side, since the relative position of the channels in the frame is known at the receivers, due to which, at least, the number of available modulation and coding schemes for different formats of the control channel information should be tested to find the appropriate modulation and coding scheme and to decode the corresponding control channel. As will be explained in more detail below, the number of blind detection attempts can be further reduced, for example, by additional (preliminary) configuration of the receivers. Thanks to the implementation according to this aspect of the invention, it is possible to provide flexibility in using different modulation and coding schemes for control signaling, although at the same time, the number of attempts to blindly detect control channels can be limited to less than or equal to the number of different control channel information formats. This is in contrast to a potentially significantly larger number of attempts, if necessary, to blindly detect the position of control channels on physical resources.

According to another aspect of the invention, there is provided a more flexible solution that allows you to take into account different geometries of mobile stations in a cell. Obviously, the coding rate for the control channel depends on the number of bits of information on the control channel to a given number of modulation symbols / resource elements and the modulation scheme used. Accordingly, the coding rate increases with the number of bits of the control channel information, if the modulation scheme and the number of modulation symbols / resource elements are not changed. This, in turn, can give coding rates for some control channels, which is unrealistic in terms of their performance, for example, for transmitting a control channel with a given block error rate (BLER) to mobile stations located at the cell boundary that are in high interference and / or low intensity of the received signal (mobile stations of low geometry).

Similarly to the above aspect, the size of the control channel information is aligned by modulation and / or coding. However, in this illustrative aspect of the invention, control channel information is aligned with one of a plurality of bits of encoded control channel information, modulation symbols, and / or CCE for each control channel. In some illustrative embodiments, the output sizes are integer multiples of the smallest output size, which allows, for example, to simplify multiplexing of control channels.

For this reason, for example, again, in the case of a fixed modulation scheme for all control channels, the encoder can output the number N ₁ or N ₂ bits of encoded control channel information for all formats of control channel information carried by the control channels, which, in turn, will be modulated in M ₁ or M ₂ modulation symbols. Alternatively, if the modulation scheme also changes, the encoder can choose the coding rate so that N encoded bits of channel information are output to the modulator for each control channel, while the modulator can use different modulation schemes (for example, depending on the geometry of the mobile stations) to modulate N encoded channel information bits in M ₁ or M ₂ modulation symbols. For this reason, in one illustrative embodiment of the invention, different numbers of encoded bits, modulation symbols and / or CCE of the control channel information format are multiples of the smallest amount of encoded control channel information, modulation symbols and / or CCE (e.g., M ₂ = n × M ₁ , where n is a positive integer), which may be advantageous, since it allows to simplify the multiplexing of control channels.

или

). Размер CCE можно задать так, чтобы наименьший размер выхода канала управления был равен одному CCE, что соответствует случаю n=0 в вышеприведенном примере.Additionally, this aspect of the invention may include further restrictions. For example, you can require that the output sizes M ₁ or M ₂ modulation symbols (also referred to here as aggregation sizes) correspond to 2 ^{n the} smallest output size (where n is an integer, for example

or

) The CCE size can be set so that the smallest control channel output size is equal to one CCE, which corresponds to the case n = 0 in the above example.

FIG. 7 shows an example of one possible configuration of a control channel in the resource grid shown in FIG. 4, according to an illustrative embodiment of the invention, and used to illustrate this additional aspect of the invention. 5 and 6, different resource element patterns in OFDM symbols associated with a control channel illustrate control channels of different users. Instead of displaying the information of the control channel of different formats in one amount of encoded information of the control channel and / or modulation symbols, according to FIG. 6, it is possible to set at least two different amounts of encoded information of the control channel and / or modulation symbols. Accordingly, each control channel information format can be associated with a modulation and coding scheme that maps the format control channel information to a first or second amount of encoded control channel information, modulation symbols, and / or CCE. Alternatively or optionally, at least some of the formats may be associated with two modulation and coding schemes to map the format control channel information into a first or second amount of encoded control channel information and / or modulation symbols. 7, it can be assumed for illustrative purposes that the control channel information is mapped to three resource elements / modulation symbols or six resource elements / modulation symbols, depending on various factors. These factors may include geometry, received signal strength, frequency and / or temporal channel selectivity of the mobile station (UE) to which the control information is intended.

Similar to the embodiments of the invention discussed in accordance with FIG. 6, this configuration of control channels may still allow simple blind detection at the receivers. Although the complexity is slightly increased due to different amounts of encoded control channel information and / or modulation symbols into which control channel information can be displayed, the number of attempts is still relatively small compared to testing all possible positions of control channels on physical resources using the only known modulation scheme and coding for all control channels, since it is assumed that the number of different formats of information of the control channel is greater than the number of times specified Erov control channel (in modulation symbols).

Note that the positions of the control channel in FIGS. 5, 6 and 7 show logical representations of the mapping of the control channel into a modulation symbol, resource element, or CCE for visualizing dimensions. The actual display of a given control channel may be distributed in the time and / or frequency domain, for example, at the level of modulation symbols, resource elements, or CCE.

The number of bits of encoded control channel information, modulation symbols, and / or CCE into which a corresponding control channel is displayed that carries control information of a specific format by modulation and coding may, for example, depend on one or more different parameters.

For example, formats having a size exceeding a certain threshold number of bits of control information may be mapped to more encoded control channel information, modulation symbols, and / or CCE than formats having a size smaller than or equal to a threshold number of bits of control information. This may be advantageous in cases where the size of the control information formats varies significantly, as this can guarantee a certain degree of reliability of the control signaling and / or maintaining an acceptable level of spectral efficiency. An illustrative embodiment is shown in FIG.

Optionally or alternatively, another decision criterion to which of the available amounts of encoded control channel information, modulation symbols and / or CCE the control channel information for the control channel (i.e., the user or group of users, respectively) is to be displayed may also depend on geometry of the user (s). For example, in the case of poor quality of the user channel (for example, measured by signal-to-noise ratio (SNR), signal-to-noise ratio (SIR), signal-to-noise plus noise (SINR), etc.) (for example, below the threshold ) and the large size of the control channel format for this user compared to other formats, the modulation and coding scheme with high spectral efficiency is most likely associated with the control channel information format for mapping the control channel to a given amount of encoded control channel information and / or modulation symbols. However, in view of the geometry of the user in the cell, this modulation and coding scheme may not provide the desired bit error rate for the control channel information. This alternative or optional criterion and the resulting mapping of control channel information of different formats into different sizes of the code block are illustrated illustratively in FIG.

The following two tables (Tables 3 and 4) provide examples of different sizes of control channel information and resulting coding rates, and for illustrative purposes it is assumed that the control channels are transmitted with QPSK modulation. In the examples, it is also assumed for illustrative purposes that the dimensions of the encoded control channel (aggregation sizes) specified in modulation symbols (resource elements (RE)) or CCE are 8, 4, or 2 times the smallest size (rightmost column, 1 CCE ) Table 3 assumes that the CCE consists of 36 REs, i.e. the smallest encoded control channel size (CCE aggregation size) is 36 RE or 1 CCE. Table 4 assumes that the CCE consists of 24 REs, i.e. the smallest encoded control channel size (CCE aggregation size) is 24 RE or 1 CCE.

Note that a given size of control channel information may represent different control channel formats, for example, size 1 control channel information may, for example, correspond to downlink allocation without MIMO and uplink without MIMO or multi-user uplink MIMO allocation, and channel information size 4 control may correspond to a single-user downlink MIMO allocation with 1 codeword and a multi-user downlink MIMO allocation. The coding rate can be calculated by the formula:

Т.е., например, скорость кодирования для размера 2 формата информации канала управления (CCI), использующего 4 CCE (согласно Таблице 3, т.е. 36 RE на CCE и модуляцию QPSK) вычисляется следующим образом: $$\text{speed}\text{coding}=\frac{\text{bits}\text{of information}\text{the channel}\text{management}}{\text{bits}\text{encoded}\text{the channel}\text{management}}=\frac{\text{bits}\text{of information}\text{the channel}\text{management}}{\text{RE number}\cdot \text{number}\text{bits}\text{in RE}}$$

That is, for example, the coding rate for size 2 of the control channel information format (CCI) using 4 CCEs (according to Table 3, i.e. 36 REs per CCE and QPSK modulation) is calculated as follows:

$$\mathrm{from}\mathrm{to}\mathrm{about}R\mathrm{about}\mathrm{from}tb\mathrm{to}\mathrm{about}d\mathrm{and}R\mathrm{about}\mathrm{at}\mathrm{but}n\mathrm{and}\mathrm{I\; am}\left(R\mathrm{but}sme\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="00000022.png,00000023.png"\; state="\{\{state\}\}">R</figure-callout>}2,\mathrm{four}CCE\right)=\frac{38}{\mathrm{one}\mathrm{four}\mathrm{four}RE\cdot 2\raisebox{1ex}{$b\mathrm{and}t\mathrm{but}$}\!\left/ \!\raisebox{-1ex}{$RE$}\right.}=0,\mathrm{one}3$$

In both of the following tables, for illustrative purposes, it is assumed that QPSK coding rates lower than, for example, 0.10 are not required, since a coding rate of, for example, 0.10 is sufficient to reach the UEs at the cell boundary. Similarly, coding rates in excess of, for example, 0.80, are not required since, for example, decoding performance (achievable BLER) is not possible due to the minimum level of decoding error). For this reason, the hatched cells in the tables indicate that the size of the control channel information is not mapped to the corresponding size of the encoded control channel.

By analogy with the above Tables 3 and 4, the following Table 5 also assumes for illustrative purposes the QPSK modulation of CCI control channel information. Unlike Tables 3 and 4 above, Table 5 shows the case when different control channel formats are used (see the “Format” column), and some of the available formats carry the same number of control channel information bits, i.e. have the same control channel information size. Similarly to the example above in Tables 3 and 4, it can be assumed that coding rates lower or higher than this threshold are not used. In addition, as can be seen, for example, in the lines (Size 2, Format 3), (Size 4, Format 6) or (Size 4, Format 7), mapping to certain sizes of CCE aggregation may be prohibited. For example, such a mapping restriction to only a subset of the available CCE aggregation sizes is possible if, for example, only specific coding rates for transmitting control channel information of a given format are necessary to provide the desired degree of transmission reliability, for example, due to the need to coordinate with this BLER for a UE at the cell boundary (limited by lower coding rates) or to avoid a minimum level of decoding error (limited by higher coding rates). Given the combination (Size 5, Format 8), the control data on the control channel may require, for example, a high level of protection, which is why only the encoding rate of 0.15 is used, i.e. The CCI of the control channel format is always displayed in 8 CCE.

Limiting the allowed CCE aggregation sizes for these formats can also help reduce the number of blind detections required by the UE. For example, if the UE needs to decode format 7 (but not formats 5 and 6), it should perform blind decoding only on 2 CCE aggregation sizes (4, 2 CCE), and not on all CCE aggregation sizes. If the UE needs to decode formats 6 and 7 (but not format 5), it still needs to perform blind decoding on 4 and 2 CCE. If the UE needs to decode formats 5, 6, and 7, it will need blind decoding of CCE 8, 4, and 2.

As will be discussed in more detail below, control channel information formats of the corresponding control channel format may optionally include an identifier that allows the receiving entity to distinguish between different formats.

In one illustrative embodiment, different control channel formats are defined as in 3GPP Tdoc. R1-074906, “PDCCH payload formats, sizes and CCE aggregation”, 3GPP TSG-RAN WG1 Meeting # 51, November 2007 (available at http://www.3gpp.org and incorporated herein by reference) :

- Format 1: uplink assignment (UL)

- Format 2: downlink assignment without MIMO (compact DL assignment) (DL-C)

- Format 3: single-user downlink MIMO assignment (1 codeword) (DL-SU1)

- Format 4: single-user downlink MIMO assignment (2 codewords) (DL-SU2)

- Format 5: assignment of multi-user downlink MIMO (DL-MU)

- Format 6: downlink diversity assignment with beamforming or open-loop transmission (DL-BF / OLT)

In this illustrative embodiment, the following mechanisms may be applied:

- MIMO formats (Formats 3, 4 and 5) are preferably applied to mobile stations (UEs) in high geometry (near the center of the cell / in conditions of only slight interference), which means that these formats are preferably transmitted with higher encoding rates, i.e. e. low coding rates not required

- the format without MIMO and the UL format (Formats 1 and 2) can be applied to all UEs in the system, for example, they are necessary for coverage at the cell boundary and are necessary for the UEs in the center of the cell without MIMO transmission, i.e. these formats can be transmitted over a wide range of coding rates

- Format 6 may not be required or may rarely be required for the UE in the center of the cell and, therefore, it is preferable to transmit it at low encoding rates.

Depending on the size of the control channel information of the appropriate format, this will lead to different sizes of CCE aggregation. An example of displaying the respective sizes of control channel information and formats is shown in Table 6 below (although the SU2 format must be transmitted displayed at high encoding rates, there may be a limitation on the lowest permissible encoding rate, as noted above, due to the minimum error level):

When working with different control channel formats having the same control channel information size, it is thus possible to take advantage of the possibility of having two or more different amounts of encoded control channel information and / or modulation symbols (CCE) for the corresponding channel information format control associated with modulation and coding schemes of different spectral efficiency, which also allows you to take into account the geometry of the user.

The selection of the amount of encoded control channel information and / or modulation symbols into which format control channel information is to be displayed can, optionally or alternatively, be carried out, for example, based on other parameters, for example, the intensity of the received signal of the control channels, fading, or downlink frequency selectivity communication lines, available transmit power, or just the type of receiver.

note that, in the general case, control channels may, for example, contain control information related to scheduling, i.e. control channel can also be called control channels associated with scheduling. In some illustrative embodiments, the control channels are L1 / L2 control channels for providing users (mobile stations) with L1 / L2 control information associated with uplink and / or downlink data transmissions on a public channel. In a number of illustrative embodiments, each control channel comprises L1 / L2 control channel information associated with uplink and / or downlink data transmission on a public channel to / from one user / mobile station. Alternatively or optionally, the control channel may optionally also carry information related to the paging call or information related to the response to the uplink (random) access procedure.

FIG. 8 illustrates an exemplary control channel information processing structure for multiple control channels at the physical layer according to an embodiment of the invention. For illustrative purposes only, processing of two control channels is shown (of course, in real systems there can usually exist more than two control channels provided in a subframe). In addition, although not shown in FIG. 8, there may be a rate matching unit between the coding unit and the modulator to adapt the coding rate of the coding unit to the desired coding rate (for example, by perforation or repetition).

Each control channel information has a specific format (or structure), i.e. control information may contain different fields and parameters. In one embodiment, the control information may be in the formats shown in FIG. 14, FIG. 15 and in Table 14 or in Table 1 and Table 2 in the Background Section. Due to the different formats, it can also be assumed that each control channel information format has a particular size, expressed by the number of bits.

Another embodiment of the invention provides for the construction of a communication circuit for control channels for an LTE design independent of the system bandwidth. This system bandwidth design is illustrated illustratively in Table 7 below (see also the aforementioned 3GPP Tdoc. R1-074906):

Table 7 Bw 1.4 MHz 1.6 MHz 3 MHz 3.2 MHz 5 MHz 10 MHz 15 MHz 20 MHz 22 MHz RB 6 7 fifteen 16 25 fifty 75 one hundred 110 Payload Size 1
[35 bit] UL
DL-BF / OLT
DL-SU1 UL
DL-BF / OLT Payload Size 2
[39 bit] DL-SU1 UL
DL-BF / OLT
DL-SU1 UL
DL-BF / OLT UL
DL-C Payload Size 3
[43 bit] DL-MU
DL-SU2 DL-MU
DL-SU2 DL-SU1 DL-BF / OLT UL
DL-C UL
DL-C UL
DL-C UL
DL-C Payload Size 4
[49 bit] DL-MU
DL-SU2 DL-MU
DL-SU2 DL-SU1
DL-MU DL-BF / OLT
DL-SU1 DL-BF / OLT Payload Size 5
[56 bit] DL-SU2 DL-MU
DL-SU2 DL-SU1
DL-MU
DL-SU2 DL-BF / OLT Payload Size 6
[65 bit] DL-SU1
DL-MU
DL-SU2 DL-BF / OLT
DL-SU1
DL-MU
DL-SU2

As follows from table 7, this format (for example, DL-C format) has different sizes of control channel information, depending on the system bandwidth. This is due to the resource block allocation (RB) field, which depends on the system bandwidth, resulting in different formats, for example, UL format (or DL-C format) and DL-SU2 format, having different sizes for the same bandwidth systems have the same control channel information size for different system bandwidths. For example, for system bandwidths of 10 MHz (50 RB) or more, the UL format (or DL-C format) is mapped to size 3 (payload) of the control channel information size. The same size is used for the DL-SU2 format (and also the DL-MU format) for the system bandwidths of 1.4 and 1.6 MHz.

Similarly, the DL-SU2 format (and also the DL-MU format) for the system bandwidths of 3.0 and 3.2 MHz is mapped to the payload size 4, which is also used for the DL-BF / OLT format for the system bandwidths of 10 and 15 MHz

Additionally, the DL-SU2 format for a system bandwidth of 5 to 15 MHz is mapped to a payload size of 5, which is also used for DL-BF / OLT format for a system bandwidth of 20 MHz.

Applying the principles established in tables 5 and 6 (formats displayed on the same size are displayed on different sizes of CCE aggregation) for different system bandwidths, for example, you can specify the display according to the following table 8.

In yet another embodiment, the CCE size may depend on the system bandwidth, moreover, the size usually increases with increasing system bandwidth. Examples are shown in tables 9 and 10. Applying the CCE numerology from table 9 to the CCE aggregation formats and sizes from table 8 gives different coding rates, as shown in table 11. As you can see, for example, for the DL-SU2 format, the same CCE aggregation sizes (2 and 4) are used for this format in all system bandwidths. This feature can simplify the operation of the base station and the UE in that blind detection of the control channel format is simplified due to the limited number of CCE aggregation sizes into which the format can be mapped.

Table 9 Bw 1.4 MHz 1.6 MHz 3 MHz 3.2 MHz 5 MHz 10 MHz 15 MHz 20 MHz 22 MHz RB 6 7 fifteen 16 25 fifty 75 one hundred 110 CCE size [RE] 24 24 24 24 24 36 36 36 36

Table 10 Bw 1.4 MHz 1.6 MHz 3 MHz 3.2 MHz 5 MHz 10 MHz 15 MHz 20 MHz 22 MHz RB 6 7 fifteen 16 25 fifty 75 one hundred 110 CCE size [RE] 16 16 twenty twenty 24 36 36 48 48

Table 12 shows another example of the application of CCE numerology from table 10 to the formats and sizes of CCE aggregation from table 8.

Regarding the processing of the control channel information at the transmitting entity, the control channel information of the corresponding control channel is first encoded and modulated by an encoder and a modulator. The encoder encodes the information of the control channel at a given coding rate (for example, in the range from 0 , 1 to 1). Different coding rates can be generated, for example, by punching or repeating the output bits of the encoder with a given original coding rate. The coded bits (also referred to herein as coded control channel information) are then modulated on a modulator. The modulator accepts groups of encoded bits (so-called codewords) or generates codewords from input encoded bits. Each codeword is then mapped by a modulator to a modulation symbol. The number of encoded bits of the codeword, therefore, depends on the level of the modulation scheme (for an M- bit codeword, a modulation scheme with 2 ^M different modulation symbols is needed). For example, a modulator may use a modulation scheme BPSK, QPSK, 16QAM, 64QAM, etc. The modulator outputs modulation symbols. For example, modulation symbols are formed by in-phase and quadrature components in the IQ plane.

As explained above, each control channel information format may be associated with at least one modulation and coding scheme. The modulation and coding scheme typically comprises the coding rate used by the encoder and the modulation scheme used by the modulator. The modulation and coding scheme (s) associated with the respective control channel information formats are selected so as to align the size of the control channel information of different formats with an equal number (or equal numbers) of bits of encoded control channel information and / or modulation symbols for each control channel.

For this reason, in this example, modulators modulating the encoded bits of the two control channels output an equal number of modulation symbols. The modulation symbols may then be multiplexed by the multiplexer and processed by an OFDM modulation unit that outputs OFDM symbols. These OFDM symbols carry control channel information and are mapped to physical channel resources, for example, as shown in FIG. 4, for transmission.

On the receiver side (here, at the mobile stations), the corresponding one of the OFDM symbols is mapped back from the resources of the physical channel at a point in time and fed to the OFDM demodulation block, which demodulates OFDM symbols to obtain a plurality of modulation symbols. The demultiplexer demultiplexes the modulation symbols and, thus, tries to restore the individual control channels. The demultiplexed modulation symbols of the corresponding control channel are then fed to a demodulator, which demodulates the symbols to generate a sequence of codewords. These codewords arrive at a decoder that attempts to recover control channel information for the corresponding control channel.

In this illustrative embodiment, it is assumed that the modulation and coding scheme for the control channels is not known to the receiving entities (with the exception of the receiving entities that are aware of the relationship between the modulation and coding schemes and the corresponding control channel formats, but not the actual formats of the control channel information on the channels). For this reason, the receiving entity can blindly detect the modulation and coding of the control channels. Note that, in the general case, according to an embodiment of the invention, certain parameters used for OFDM demodulation, demultiplexing, demodulation and decoding can be known to receiving entities, for example, due to (preliminary) configuration, however, not all parameters necessary for accessing are available processing of the physical layer, therefore, at some stages of processing the physical channel, the receiver needs to find suitable parameters by trial and error, i.e. blind detection.

One example of blind detection is that a receiver (mobile station) demodulates the received signal and attempts to decode the control channels using one of the different modulation and coding schemes that were specified for the control channel information formats. The blind detection mechanism for use in one embodiment of the invention is similar to that described in Section 4.3.1 and Appendix A in 3GPP TR 25.212: "Multiplexing and channel coding (FDD)", Release 7, Version 7.1.0, June 2006 and in 3GPP TSG-RAN WG1 # 44 R1-060450, "Further details on HS-SCCH-less operation for VoIP traffic", February 2006 or 3GPP TSG-RAN WG1 # 44bis R1-060944 "Further Evaluation of HS-SCCH-less operation ", March 2006 (all three documents are available at http://www.3gpp.org and are incorporated herein by reference).

FIG. 9 shows another exemplary control channel information processing structure for multiple control channels at the physical layer according to an embodiment of the invention. In essence, the same processing steps are provided for the control channels as in FIG.

First, the control channel information for all corresponding control channels is individually encoded by an encoder (coding unit). Similar to FIG. 8, there may be a rate matching unit between the coding unit and the modulator to adapt the coding rate of the coding unit to the desired coding rate (for example, by punching or repeating). In contrast to the physical layer processing in FIG. 8, encoded channel bits outputted by encoding are multiplexed in this embodiment, and the multiplexed encoded control channel bits are modulated on a modulation unit. For this reason, in this illustrative embodiment, the modulation scheme for all control channels is the same. Accordingly, in order to equalize the size of the information of the control channel of different formats, the coding rate of the modulation and coding scheme associated with the corresponding control channel should be selected so that the coding unit outputs an equal amount of encoded information of the control channel for all control channels. (By using the same modulation scheme for all control channels in this example, modulating the encoded bits of each control channel also results in an equal number of modulation symbols / resource elements for each control channel).

Modulation symbols for control channels output by the modulation unit are OFDM modulated and mapped to a physical channel, as explained above with respect to FIG. Accordingly, the reverse processing on the receiver side is similar to that described with reference to Fig. 8, except that the demodulation of the symbols provides a stream containing the code words of all control channels, which must be demultiplexed to obtain code words of the corresponding control channels. Decoding attempts are made over the code words of the respective control channels to recover control channel information for all corresponding control channels.

Alternatively, multiplexing at the transmitter can also be performed after modulation. Accordingly, the receiver must also be capable of demultiplexing prior to decoding. In addition, in yet another embodiment of the invention, optional steps may be performed on the transmitter before being mapped to a physical channel, for example, scrambling, interleaving, etc. Similar measures to reverse the effect of the respective steps should be provided, respectively, on the receiver. In addition, in the case where the control channels are displayed in the CCE, optional steps related to the display in the CCE and multiplexing at the transmitter and the corresponding steps (demultiplexing and unmapping) at the receiver may be provided.

FIG. 10 shows, in accordance with an illustrative embodiment of the invention, the use of two different modulation and coding schemes having a common modulation scheme to equalize the number of bits of encoded control information for control channel information for control channels, where the control channel information has different formats. In this example, for illustrative purposes, two different formats of control channel information are considered, format 1 and format 2, with different sizes. It is assumed that the control channel format 1 for the first control channel has a size of 12 bits, and the control channel format 2 for the second control channel has a size of 18 bits. (Note that from the above table 1, table 2 and table 3, as well as from FIG. 14 and FIG. 15, it follows that in a real implementation, control channel information formats usually have more than this rather small number of bits, and that embodiments described according to Fig.10-Fig.13 should be considered as an illustration of the idea). The size of two different formats of control channel information should be aligned in this example. To this end, each of the two formats is associated with a modulation and coding scheme. Format 1 is associated with a modulation and coding scheme {coding rate: 1/3; modulation scheme: 16QAM} and Format 2 is associated with a modulation and coding scheme {coding rate: 1/3; modulation scheme: 16QAM}. Accordingly, the control channel modulation scheme can, for example, be pre-configured in this example. For this reason, in order to equalize the size of the information of the control channel, the coding rate of the corresponding modulation and coding scheme for format 1 and format 2 was chosen so that when coding an equal number of coded bits are obtained. 12 format 1 bits are encoded at a 1/3 coding rate, resulting in 36 encoded bits. Likewise, 18 bits of format 2 are encoded at a coding rate of ½, which also results in 36 encoded bits.

Since 16QAM modulation is used, when modulating, 4-bit code words are mapped to a single modulation symbol. For this reason, in this example, when modulating 36 encoded bits of the respective control channels, 9 modulation symbols for each control channel are obtained. Note that, of course, it is possible to provide more than two control channels for transmission at a given time, and that it is also possible to provide more than two formats of control channel information. Accordingly, it is necessary to provide a modulation and coding scheme for each format of the control channel information (provided that the formats differ in size).

In yet another embodiment, the at least two control channel information formats of the possible control channel information formats are of the same size. Accordingly, in order to display these at least two pieces of control channel information into an equal number of coded bits or modulation symbols, care must be taken to ensure that the modulation and coding schemes for these equal-sized formats are different from each other.

If one parameter of the modulation scheme is to be used for all formats (for example, the general modulation scheme is to be used for all control channels regardless of the format), the same modulation and coding scheme will be used for these formats of control channel information of equal size. For this reason, in order to still be able to identify the correct control channel format, in yet another embodiment, the receivers can decode the control channel information and can compare the resulting control channel information with formats of equal size to identify the correct format. Alternatively, in yet another embodiment, it may advantageously include a format identifier (for example, a control channel information format field) in the control channel information or in coded bits (by an encoder) to uniquely identify the format of the control channel information. Note that the identifier of the control channel format can also be used by default, i.e. regardless of whether there are equal-sized control channel formats, or whether control channel information formats are displayed in different numbers of encoded bits or modulation symbols.

If all formats of the information of the control channel have a different size (measured by the number of bits) of the modulation and coding schemes for the corresponding formats, all will be different, so an identifier is not required.

Additionally, the selected control channel information formats may be of the same size, however, this mobile station may not need to decode all formats. Instead, a mobile station can use only one of them. In this case, a format identifier is not required. This can be realized, for example, by preconfiguring the mobile station (UE) to receive only control channels for the single user downlink MIMO mode. Accordingly, the mobile station does not need to decode other formats, for example, without MIMO or multi-user MIMO. Thus, even if the formats are the same size, the mobile station only needs to know how to interpret the contents of the control channel, in which case the format identifier is not required.

Alternatively, if the different formats of the control channel information are of the same size, they can be mapped onto the exceptional CCE aggregation sizes. In this case, a format identifier may also not be required, since the format is known from the CCE aggregation size. This is illustratively shown in table 13.

Alternatively or optionally, in yet another embodiment of the invention, different control channel formats can also be distinguished by applying different interleaving and / or scrambling schemes to the control channel information, depending on the corresponding control channel format. For example, each of the different control channel formats may be associated with different interleaving schemes for the data of the control channel information. Additionally, there is a unique mapping between the control channel format and the corresponding interleaving scheme, i.e. control channel formats may be associated with mutually different interleaving schemes.

Similarly, different scrambling codes can, for example, be applied to control channel information, wherein the applicable scrambling code is selected based on the control channel format for the control channel information. Optionally, it is possible to provide a unique mapping between the control channel format and the corresponding scrambling code, i.e. control channel formats may be associated with mutually different scrambling codes.

Note that the selected interleaving scheme or scrambling code may additionally depend on other parameters, for example, CCE aggregation size, cell identifier (cell ID), radio cell where the mobile station (UE) is located and / or mobile station identifier (UE ID )

In addition, note that according to one illustrative embodiment of the invention, different interleaving schemes are obtained using the same interleaving algorithm, the algorithm is initiated by different values of the initialization parameter.

Similarly, different scrambling codes can, for example, be generated using a general algorithm for generating scrambling codes and initializing this algorithm with different values of the initialization parameter depending on the format of the control channel.

11 shows, in accordance with an illustrative embodiment of the invention, the use of two different modulation and coding schemes to equalize the number of modulation symbols of control channel information for control channels, where the control channel information has different formats and sizes. In this illustrative embodiment, a modulation scheme for different formats is not predetermined. Accordingly, it is not required (but still possible) that the number of coded bits for different formats coincides.

In this illustrative embodiment, again, two different control channel formats, format 1 and format 2, are considered for illustrative purposes. The control channel format 1 is associated with a modulation and coding scheme {coding rate: 1/3; modulation scheme: 16QAM}, and the control channel information format 2 is associated with the modulation scheme {coding rate: 1/2; modulation scheme: QPSK}.

Accordingly, 12 bits for format 1 are first encoded at ½, resulting in 36 encoded bits. Then these encoded bits are subjected to 16QAM modulation (codeword size: 4 bits) to obtain 9 modulation symbols. Similarly, 9 format 2 bits are encoded at ½, resulting in 18 encoded bits. These encoded bits undergo QPSK modulation (codeword size: 2 bits), resulting in 9 modulation characters, as well as for format 1.

Thus, in FIG. 10 and FIG. 11 illustratively shows the encoding and modulation step in the processing of control channels at the physical level, shown, for example, in FIG. Although in the example of FIG. 10, the number of coded bits matches one number of coded bits for all control channel formats, FIG. 11 shows an example where the number of modulation symbols for all control channel information formats is the same.

As indicated above, another aspect of the invention relates to a more flexible configuration of the control channel, which can still facilitate the blind detection of control channels on the physical resources of the downlink without further complicating the receiving objects.

12 shows, in accordance with an illustrative embodiment of the invention, the use of different modulation and coding schemes to equalize the number of modulation symbols of control channel information for control channels with two numbers of modulation symbols, where the control channel information has different formats. In this illustrative embodiment, for illustrative purposes, there are three different formats of control channel information of different sizes. It is assumed that the control channel information format 1 has a size of 12 bits and is associated with a modulation and coding scheme {coding rate: 1/3; modulation scheme: 16QAM}. It is assumed that the control channel information format 2 has a size of 9 bits and is associated with a modulation and coding scheme {coding rate: 1/2; modulation scheme: QPSK}. It is assumed that the control channel information format 3 has a size of 18 bits and is associated with a modulation and coding scheme {coding rate: 1/2; modulation scheme: QPSK}. For this reason, format 2 and format 3 are associated with the same modulation and coding scheme, but the resulting number of modulation symbols will be different due to different sizes from the two formats.

In the case of applying the modulation and coding scheme 1 of the format and format 2 to the corresponding control channel information, 9 modulation symbols will be obtained for the control channel information formats 1 and 2. For control channel information format 3, encoding its 18 bits at 1/2 coding rate produces 36 encoded bits, and subsequent QPSK modulation generates 18 modulation symbols. For this reason, in this illustrative embodiment, applying a modulation and coding scheme associated with different formats of control channel information to control channel information for control channels leads to the generation of 9 modulation symbols or 18 modulation symbols.

As explained above, there may be various reasons for generating two different numbers of modulation symbols (or encoded bits) for different control channel formats. One reason may be that to generate 9 modulation symbols for format 3, a modulation scheme with high spectral efficiency is required (eg {coding rate: 1/2; modulation scheme: 16QAM}). However, this modulation and coding scheme may be too unreliable for transporting control channel information (for example, due to channel conditions) or it may be a modulation and coding scheme that is simply not allowed for use with control signaling, and therefore cannot be used. For this reason, it is possible to set a second number of coded bits or modulation symbols with which control channel information can be matched.

Although it is assumed in FIG. 12 that different control channel information formats are assigned to one modulation and coding scheme, in yet another embodiment, different control channel information formats can be assigned to two (or even more) modulation and coding schemes, due to which it is selectively different, but data / known amounts of coded bits or modulation symbols may be generated for all control channel information formats. For example, in the system, you can specify three numbers of modulation symbols, designated M ₁ , M ₂ and M ₃ . Accordingly, different formats of the control channel information can be assigned to at least one and at most up to three different modulation and coding schemes for displaying the control channel information of the corresponding formats into one or a combination of M ₁ , M ₂ and M ₃ modulation symbols. For example, format 1 may be associated with two modulation and coding schemes displaying control information of this format in M ₁ or M ₂ modulation symbols, format 2 may be associated with three modulation and coding schemes displaying control information of this format in M ₁ , M ₂ or M ₃ modulation symbols, and format 3 may be associated with two modulation and coding schemes displaying control information of this format in M ₂ or M ₃ modulation symbols. In one embodiment, the amounts of M ₁ , M ₂ and M ₃ can be selected so that (provided that M ₁ is the smallest number) M ₂ = n × M ₁ and M ₃ = m × M ₁ (n and m - different positive integers). A CCE can be defined as a set of M ₁ modulation symbols and, therefore, aggregation of n (m) CCE will give M ₂ (M ₃ ) modulation symbols. Alternatively, the CCE size can be set so that M ₁ modulation symbols specify k CCE, therefore aggregation of k × n (k × m) CCE will give M ₂ (M ₃ ) modulation symbols.

This flexible specification of different numbers of coded bits or modulation symbols with which different control channel information formats can be matched allows adaptive modulation and coding for control channels to be used, for example, to respond to changing channel conditions, as will be explained later on in accordance with FIG. 13 . FIG. 13 shows, in accordance with an illustrative embodiment of the invention, the use of different modulation and coding schemes to equalize the number of modulation symbols of control channel information for a control channel with two number of modulation symbols (CCE), where the control channel information has different formats. The decision as to whether to display the control channel information in the first number of modulation symbols or in the second number of modulation symbols can be based, for example, on the quality of the channel or the geometry of the user for whom the control channel information is transmitted, as mentioned above. Another parameter for such a solution may also be the format of the information of the control channel, which is displayed in a given size of information of the control channel. For example, in this embodiment of the invention, two (or more) modulation schemes may be defined for the control channel format. Depending on the channel quality of the downlink physical channel carrying the control channels, one of the modulation and coding schemes for the formats can be selected, respectively. For example, if the channel quality is below a certain threshold value, a modulation and coding scheme can be used for information of a control channel of a given format that provides lower spectral efficiency / data rate than a second modulation and coding scheme for information of a control channel of a given format that is applied, if the quality of the channel is higher or equal to the threshold level. In yet another embodiment, adaptive modulation and coding, as well as power control, can be applied to the L1 / L2 control channels, i.e. L1 / L2 control signaling to a mobile station near the center of the cell (high geometry / SINR) must be transmitted with low power and / or high MCS (fewer modulation symbols or CCE), while L1 / L2 control signaling on MS near the cell boundary (low geometry / SINR) must be transmitted with a high power level and / or low MCS (a large number of modulation symbols or CCE).

Accordingly, if there are more than two modulation and coding schemes, i.e. N modulation and coding schemes defined for the corresponding format, N-1 thresholds can be set to distinguish between different ranges of the channel quality level in which different modulation and coding schemes are to be used. It may also be advantageous to select the level of the modulation and coding scheme in direct proportion to the quality of the channel, i.e. choose a lower level modulation and coding scheme (i.e., providing a lower data rate / spectral efficiency) for lower channel quality and a higher level modulation and coding scheme (i.e. providing a higher data rate / spectral efficiency) for higher quality channel.

On Fig shows several different formats of information of the control channel and their display in a single code block size by modulation and coding according to an illustrative embodiment of the invention. On Fig shows six different illustrative formats of information of the control channel. In general, it should be understood that a part of the control channel information can be considered as a location indicator of a data block containing user data for an individual user in the data part of a subframe (or several consecutive subframes). In other words, the control data can indicate to the user whether the mobile station (user) is assigned (s) and, if so, which resource block (s), which transport format (link adaptation) is used to transmit user data, intended for a mobile station, etc.

According to some embodiments of the invention, the structure or format of the information carried by the control channels can be divided into categories: public control information (SCI) and dedicated control information (DCI).

The SCI part of the control signaling may contain information related to resource allocation (also referred to as Cat. 1 information). The SCI part may comprise a user identifier (UE ID field) indicating the user (or group of users) to whom the resource is allocated, RB allocation information indicating resources (resource block (s)) allocated to the user. The resource allocation field may indicate the resource block (s) allocated for uplink user data transmission on the uplink data channel or, alternatively, the resource block (s) to be used (e) for transmitting user data on the downlink to the corresponding mobile station or group of mobile stations identified by the UE ID field on the downlink public channel (for example, the downlink public channel (DSCH) for SAE / LTE systems). The number of resource blocks allocated to the user can be dynamic. Additionally, the SCI may further include an indication of the duration of the assignment, if the assignment of multiple subframes (or TTI) is possible in the system.

The DCI part of the control signaling may contain information related to a transmission format (also referred to as Cat. 2 information) of data transmitted to a scheduled user specified by Cat. 1. In addition, when using (mixed) ARQ, DCI can also carry information related to the retransmission protocol (also referred to as Cat. 3 information), such as (H) ARQ information. DCI should only be decoded by users scheduled according to Cat. one.

Information Cat. 2 in DCI may, for example, contain information about at least one of a modulation scheme, size (or coding rate) of a transport block (payload), information related to MIMO, etc. Information Cat. 3 may contain HARQ related information, for example, mixed ARQ process number, redundancy version, retransmission sequence number. Note that either the transport block size (payload size) or the coding rate can be signaled in Cat. 2. In any case, the payload size and coding rate can be calculated from each other using the modulation scheme information and resource information (the number of allocated resource blocks).

In the case where the MIMO scheme is used or is to be used to transmit user data, it may be necessary to provide several information elements in the control channel information for each of the MIMO streams. Accordingly, some information elements can be provided several times in the illustrative L1 / L2 control information, for example, for each MIMO stream. In addition, it is possible that some of the various parameters (for example, payload size, modulation scheme, etc.) are to be used by all or a subset of the MIMO streams.

The first illustrative format shown in FIG. 14 is a simple control channel information format that can be used on control channels for users not using any particular MIMO scheme (for example, SISO — one input, one output, or simple transmit diversity and / or reception that does not require additional information related to the antenna). This format may, for example, contain only RB allocation information, the identification of the user (s) for whom the management information is intended (for example, by means of the UE ID field or by implicit identification, for example, CRC depending on the UE), the size of the payload (respectively, transport format, as explained above), modulation scheme information and HARQ.

A second illustrative format can be used, for example, for transmitting user data using a MIMO scheme. By analogy with the first format shown in FIG. 14, this format also contains RB allocation information, identification of the user (s) for whom control information is intended, payload size (transport format respectively), modulation scheme information and HARQ. In addition, the format may further include information elements, including the number of MIMO streams and precoding information (for example, the number of MIMO streams and the precoding vector or index value indicating a preconfigured precoding vector). As just one “set” of information elements related to the size of the payload, modulation scheme information and HARQ, this may mean that all streams indicated in the stream number field use the same payload size and modulation scheme, and that all threads can be processed in a single HARQ process. Alternatively, payload size, modulation scheme, etc. only a subset (for example, one) of the multiple streams is configured, and information about additional streams is transmitted separately.

The third control channel information format shown in FIG. 14 contains the same information elements as the second example, except that it is assumed that more precoding information is included in the control information (e.g., a larger precoding vector for example, an index reflecting a larger index space).

Then, a fourth example of a control channel information format also relates to the use of a 2-stream MIMO scheme. In this example, different payload sizes are used for the respective MIMO streams, so these two payload size fields are included in the format. By analogy with the previous examples, the same modulation scheme can be used for both MIMO streams, and the streams can be processed in a single HARQ process. Alternatively, modulation and HARQ information may configure one stream, and information about the second stream is transmitted separately, for example, on another control channel.

The fifth illustrative format of FIG. 14 is substantially similar to the fourth example, except for the use of two separate HARQ processes for the respective MIMO scheme streams. Similarly, the sixth exemplary L1 / L2 control information format shown in FIG. 14 suggests two different payload sizes and two different modulation schemes for two MIMO streams, although both streams are processed in a single HARQ process.

In general, the control channel information may partially or fully contain information for multiple MIMO streams for various MIMO configurations.

As follows from the illustrative control channel information shown in FIG. 14, the format of the control information on the control channels may vary depending on the configuration used to transmit user data. Accordingly, different formats may not only differ in their content, i.e. information elements contained in the appropriate format and / or size (measured by the number of bits) of the formats. The format of the control channel information may, for example, depend on at least one of the following parameters:

- communication of the control channel with the MIMO scheme or beamforming scheme used or to be used to transmit user data,

- communication of the control channel with the transmission of user data on the uplink or downlink,

- control channel communications using OFDM transmission in local mode or in distributed mode to transmit user data.

Note that the examples shown in FIGS. 14 and 15 are intended to illustratively visualize at an abstract level that various other control channel formats may exist, resulting in different sizes of control channel information. There may be additional fields defined for specific formats (for example, power control commands for different channels, information related to multi-user MIMO, format identifiers, etc.) that are not shown.

In addition, some fields may be omitted because their information can be derived from other fields (for example, because the fields are combined into other fields or because the corresponding information is transmitted through another channel or pre-configured). Some examples of how to obtain individual control channel information parameters from each other are given in illustrative order below:

- modulation scheme information can be derived from the payload size and RB allocation information

- HARQ information may not be required for certain control channel formats

- the number of MIMO streams can be derived from some other fields the control channel and / or can be pre-configured

In addition, certain control channel information fields may have different sizes in different control channel formats, for example:

- the RB allocation information field may be smaller for the first format to keep this control channel format as small as possible (to improve coverage, since a small format size gives a lower encoding speed / higher encoding gain). However, this may create some limitations regarding the flexibility of RB isolation.

- for the uplink control channel, “the RB allocation information field may be less than for some downlink control channels

For this reason, according to FIG. 14, a modulation and coding scheme for respective control channels can be selected based on the format of the control information on the corresponding control channel in order to equalize the size of the control channel information on the physical resource. According to yet another embodiment, different control channel formats, as shown in FIG. 14 and FIG. 15, can also be mapped to two different code block sizes (i.e., the number of bits of encoded control information), as shown in FIG.

The following table shows an illustrative definition and overview of the contents of control channels according to an illustrative embodiment of the invention. Note that the size of the corresponding fields is for illustrative purposes only.

Table 14 Field The size Comment cat. one
(Resource Indication) ID (for UE or group) 8 Indicates the UE (or group of UEs) for which data transmission is intended; the indication may be implicit, for example, in the form of a CRC

Assigning Resources 6 Indicates which (virtual) resource blocks (and layers in the case of multi-level transmission) should (us) demodulate the UE. Duration of appointment 2 The validity period of an assignment can also be used to control TTI or continuous scheduling. cat. 2
(transport format) Multiple Antenna Information 0-20 The content depends on the choice of MIMO schemes / beamforming. Modulation scheme 2 QPSK, 16QAM, 64QAM. In the case of multi-level transmission, multiple instances may be required. Payload size 6 The interpretation may depend, for example, on the modulation scheme and the number of assigned resource blocks (see HSDPA). In the case of multi-level transmission, multiple instances may be required. cat. 3
(HARQ) If accepted asynchronous mixed ARQ Mixed ARQ Process Number 3 Specifies the mixed ARQ process that the current transfer is accessing. Redundancy Version 2 To support increasing redundancy. New data indicator one For carrying out soft buffer cleaning.

If synchronous mixed ARQ is accepted Retransmission Sequence Number 2 Used to get the version with redundancy (To support increasing redundancy) and the 'new data indicator' (To implement soft buffer cleaning).

Other embodiments of the invention relate to limiting the number of blind detection attempts to further simplify the configuration of the control channel. To limit / reduce the number of blind detection attempts by the receiver (mobile station, UE), the receiver may, for example, try to detect only a subset of the possible specified formats and sizes (resources) of the L1 / L2 control signaling.

This may require some configuration. The corresponding configuration mainly affects the receiver, but can, in some cases, affect the transmitter.

In one illustrative embodiment, the receiver is configured so that it only tries to accept a subset of formats and / or a subset of sizes (MCS levels for certain formats). The receiver can, optionally or alternatively, be configured so that it attempts to receive control channels only on some of the physical resources used for control channels.

In one illustrative scenario, the receiver can be pre-configured in MIMO 1 mode for the downlink and, thus, it tries to accept only the format specified for MIMO 1. Additionally, this mobile station may try to receive only a certain code block size for this format 1 MIMO mode control channel information. In addition, the mobile station may also attempt to receive this format 1 MIMO mode only on a subset of the control channel resources.

In another illustrative scenario, the mobile station may act on the uplink and downlink. This mobile station can thus receive uplink control channels on a first subset of all control channel resources, and can also receive downlink control channels on a second subset of all control channel resources.

In many cases, this operation may imply that the transmitter has limited flexibility with respect to displaying certain control channel formats only to certain resources. This can be considered as a transmitter configuration. In general, transmitter flexibility may be limited by receiver complexity (UE) (the number of possible blind detection attempts).

In one illustrative embodiment of the invention, the configuration of the receivers is carried out by the network (transmitter). The configuration may be general information for all receivers, which may be broadcast by the access network. Alternatively, the configuration may be dedicated to a single receiver or group of receivers. In this alternative, dedicated signaling may be used to transmit configuration to receiver (s). The general configuration may be transmitted, for example, on a broadcast channel, and the dedicated information may be transmitted, for example, on a dedicated channel or a public channel. In some cases, you can use a combination of general and dedicated configuration. For example, a receiver may be initialized through a basic general configuration (through broadcasting) and may be reconfigured through dedicated signaling.

In addition, configuration can be performed dynamically for each subframe. In one illustrative embodiment, the so-called control channel cat. 0 can be configured in the communication system to provide information about the currently transmitted formats, sizes and / or resources of the control channel. For example, in this subframe, information cat. 0 may indicate that only control channels are transmitted associated with the transmission of user data on the uplink (or, alternatively, the transmission of user data on the downlink), so that only interested receivers may need to receive control channels. In another example, information cat. 0 may indicate that control channels contain only control channel information (and thus corresponding control channel formats) for particular MIMO modes. In another example, control information cat. 0 may indicate that control channels are transmitted only on certain resources of the control channel or may indicate that control channels carry only control channel information of certain sizes.

Information Cat. 0 does not have to be transmitted for each subframe. It can also be transmitted on a larger time scale, and the transmitted information may be valid for a certain period of time.

As for embodiments of the invention, providing for multiple sizes of a code block from a single control channel format (see, for example, FIG. 7, FIG. 12, FIG. 13 and FIG. 15), the state of the mobile stations determined by the geometry / SINR (signal ratio to interference plus noise). For example, mobile stations MS1 and MS2 may be located on the border of a radio cell, and therefore it can be assumed that the quality of their radio channel is lower than the quality for mobile stations MS3 and MS4, which are supposedly closer to the center of the radio cell. In order to transmit control signaling safely, stations MS1 and MS2 are thus assigned more resources on the control channel, i.e. control channel format 1 is modulated and encoded to generate a larger code block (i.e., the number of encoded control channel information) or a larger number of modulation symbols, while MS3 and MS4 having a higher channel quality receive control signaling with a higher MCS level , i.e. the control channel format 1 is modulated and encoded to generate a smaller code block (i.e., the amount of encoded control channel information) or fewer modulation symbols.

In yet another embodiment of the invention, control signaling (i.e., control channel information for control channels) and user data may be multiplexed. This can be realized, for example, by TDM (time division multiplexing), as shown in FIG. 6 and FIG. 7, FDM (frequency division multiplexing), CDM (code division multiplexing), or allocating time-frequency resources in a subframe. In addition, different control channels themselves can be multiplexed in CDM, TDM and / or FDM mode. In one illustrative embodiment, user data multiplexing is performed through a combination of TDM and FDM, i.e. multiplexing can be done at the level of resource elements, while control channels are multiplexed through a combination of CDM and FDM. This illustrative embodiment is shown in FIG. The left side of the figure shows an OFDM channel subframe resource grid in which control channels of two sets are mapped to a physical resource in distributed mode. The right side of the figure shows an OFDM channel subframe resource grid in which control channels of two sets are mapped to a physical resource in local mode.

In the example of FIG. 1, L1 / L2 control information is transmitted over several L1 / L2 control channels. According to one illustrative embodiment, the L1 / L2 control channels can be mapped onto a portion of the physical resource blocks and evenly distributed across all the physical resource blocks. In general, the mapping of L1 / L2 control channels to blocks of physical resources can be done in different ways. For example:

- Control channels can be evenly distributed across all blocks of physical resources (as shown in figure 1).

- Control channels can be unevenly distributed across all blocks of physical resources.

- Control channels may (not) be evenly distributed over selected blocks of physical resources (for example, as shown in FIG. 19).

Individual pieces of L1 / L2 control information may be encoded in different ways. According to one illustrative embodiment, the information cat. 1, cat. 2 and cat. 3 is coded together for each mobile station. Another option is to encode Cat. 1, separately from Cat. 2 and cat. 3 for each mobile station.

Details regarding coding and display in a subframe for different categories of L1 / L2 control signaling for use in another illustrative embodiment of the invention can also be found in 3GPP RAN WG # 1 Tdoc. R1-061672: "Coding Scheme of L1 / L2 Control Channel for E-UTRA Downlink", June 2006, available at http://www.3gpp.org and incorporated herein by reference.

In some embodiments of the invention, the control information (L1 / L2) is transmitted more reliably than user data, since correct decoding of the control information may be a prerequisite for the start of demodulation and decoding of user data. This usually implies that the target block error frequency for control signaling should be lower than the target block error frequency for user data. In the case of (mixed) ARQ, this assumption refers to the target block error rate for the first transmission.

In addition, note that the principles of the invention, presented in various illustrative embodiments, can be advantageously used in the mobile communication system described in FIG. 16. A mobile communication system may have a “two-node architecture” consisting of at least one Access and Core Gateway (ACGW) and Node B. The ACGW can perform core network functions, for example, route calls and data connections to external networks, and can also implement some RAN functions. Thus, ACGW can be considered as a combination of functions performed by GGSN and SGSN in modern 3G networks and RAN functions, for example, radio resource management (RRC), header compression, encryption / integrity protection and external ARQ. Nodes B can perform functions such as segmentation / concatenation, scheduling and resource allocation, multiplexing and physical layer functions. For illustrative purposes only, eNode B nodes controlling only one radio cell are shown. Obviously, using directional antennas and / or other methods, the eNode Bs can control multiple radio cells or logical radio cells.

In this illustrative network architecture, a public data channel can be used to communicate on the uplink and / or downlink over the air interface between mobile stations (UEs) and base stations (eNode Bs). This public data channel may have the structure shown in FIG. 3 or FIG. 4. Thus, the channel can be considered as a concatenation of subframes, illustratively presented in Fig.6 or Fig.7. According to an illustrative embodiment of the invention, the public data channel can be set as in the "Background" section, as in 3GPP TR 25.814 or as HS-DSCH defined in 3GPP TS 25.308: "High Speed Downlink Packet Access (HSDPA); Overall description ; Stage 2 ", version. 5.3.0, December 2002, available at http://www.3gpp.org and incorporated herein by reference. The downlink public channel can be used to transfer control channels to individual users (UEs).

In addition, note that the different sizes of control channel information indicated in the various tables here are illustrative only. Note that the exact number of bits of the respective formats, as well as the number of formats specified for the control channels, may differ from the examples shown here in various tables and figures. However, the principles set forth here are applicable.

According to yet another embodiment of the invention, it is contemplated to implement the above-described various embodiments using hardware and software. Obviously, various embodiments of the invention can be implemented or implemented using computing devices (processors). The computing device or processor may, for example, be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), user-programmable gate array (FPGA), or other programmable logic device, etc. Various embodiments of the invention may also be practiced or embodied by a combination of these devices.

In addition, various embodiments of the invention can also be implemented through software modules that are executed by the processor, or directly in the equipment. In addition, a combined implementation of software modules and equipment is possible. Software modules can be stored on any computer-readable medium, for example, RAM, EEPROM, EEPROM, flash memory, registers, hard drives, CD-ROMs, DVDs, etc.

Various embodiments of the invention and various variations thereof have been described previously. Specialists in the art can offer numerous variations and / or modifications of the present invention, as shown in specific embodiments, without departing from the essence and scope of the invention described in a generalized form.

It should also be noted that most embodiments have been described with respect to the 3GPP communication system, and the terminology used in the previous sections mainly refers to 3GPP terminology. However, the terminology and description of various embodiments according to 3GPP architectures are not intended to limit the principles and ideas of the invention to such systems.

The detailed description given in the Background section above is intended to better understand the most illustrative 3GPP related embodiments described herein, and should not be construed as limiting the invention to the described specific implementations of processes and functions in a mobile communication network. However, the limitations proposed in this description can be easily applied to the architectures described in the "Background" section. In addition, the principles of the invention can also be easily used in the LTE RAN currently under consideration in 3GPP.

Claims (4)

1. A method for receiving control information from a plurality of control information formats on control channels in a mobile communication system in which each of the control channels is configured according to one of a plurality of control information formats differing in the number of bits, the method comprising the steps of:
take the number of elements of a physical resource containing modulated control information of at least one of the control channels,
demodulating the modulated control information of at least one control channel using this modulation scheme to obtain bits of encoded control channel control information, and
decode bits of encoded control information of at least one control channel,
get the number of bits of encoded control information, which is an integer multiple of the smallest allowable number of bits of encoded control information for all formats of control information. 2. The method according to claim 1, in which the modulated control information is transmitted on the resource elements of the physical control channels of the downlink, and the method further comprises a step on which blind detection is carried out only on a subset of the elements of the physical resource onto which the modulated control information can be displayed, and / or only on a subset of control information formats. 3. The method according to claim 1 or 2, the method being carried out by an object of the receiving party in communication with the base station. 4. The method according to claim 3, in which the object of the receiving side is a mobile station.

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